Sports Network

Philadelphia - Minnesota quarterback Brett Favre remains doubtful for Tuesday's game at Philadelphia after suffering a concussion in last Monday's loss to Chicago.

According to the Minneapolis Star-Tribune, Vikings' head coach Leslie Frazier said the 41-year-old signal caller has still not passed the initial part of his concussion test.

To be able to play, Favre would also have to pass a conditioning part of the test.

Should Favre not be able to go, rookie Joe Webb, who took over for Favre after he was knocked out of last week's game in the second quarter, would be given his first career starting assignment.

The extra time off could give running back Adrian Peterson the opportunity to play in Tuesday's game. He was listed on the injury report as questionable and likely would not have played had the game gone off as scheduled Sunday night.

Minnesota safety Madieu Williams, who was also listed as questionable going into the game on Sunday after suffering a concussion against Chicago, has passed part of his concussion test and could be available on Tuesday.